A bipolar resistive switch, also often referred to as a ‘memristor,’ is an electrical device having or exhibiting an instantaneous resistance state that is a function substantially of bias history. In particular, a bias (e.g., a voltage or a current) applied across terminals of the bipolar resistive switch may be used to set, select or program a device state (e.g., a resistance) of the bipolar resistive switch. Once programmed, the bipolar resistive switch may retain the device state for a specified period of time after the bias is removed. As such, a bipolar resistive switch is a two-terminal device that may function as a non-volatile memory where the programmed device state stores information.
In some examples, the bipolar resistive switch or memristor may be switched between a specific pair of device states using a programming signal having two different polarities (e.g., a positive voltage and a negative voltage). For example, the bipolar resistive switch may be switched to a first or ‘ON’ device state (e.g., a relatively low resistance state) by a first polarity of the programming signal. Alternatively, the bipolar resistive switch may be switched to a second or ‘OFF’ device state (e.g., a relatively high resistance state) by a second polarity of the programming signal. Such ‘bipolar switching’ may be used to implement a binary memory cell or element, for example. Further, a plurality of bipolar resistive switches may be arranged in an array (e.g. a cross-bar array) to serve as a binary memory for storing data in a computer system or as programmable logic, according to various applications.
Certain examples have other features that are one of in addition to and in lieu of the features illustrated in the above-referenced figures. These and other features are detailed below with reference to the above-referenced figures.